Botnets are responsible for hacking, spamming, and malware—here are the most significant botnet attacks with the worst consequences.

Individual systems, commonly known as zombies, combined with the criminal’s system (from where all other systems are controlled) are known as a master of the zombie network or “bot-network.” A bot-network can deliver a DDoS attack on a large-scale. Botnets target to send millions of spam emails, pull the websites down for ransom, or harm the victim financially or even emotionally.

EarthLink Spammer—2000

EarthLink Spammer is the first botnet to be recognized by the public in 2000. The botnet was created to send phishing emails in large numbers, masked as communications from legitimate websites. Over 1.25 million malicious emails were sent to collect sensitive information, such as credit card details, in the span of a year.

Cutwail—2007

Cutwail, a malware that targets Windows OS through malicious emails, was discovered in 2007. The malware was distributed via the Pushdo Trojan to turn the infected system into a spambot. Message Labs, a security organization, identified that Cutwail had compromised 1.5–2 million infected systems and was capable of sending 74 billion spam emails per day.

Storm—2007

Storm may not be the most malicious piece of malware in the history of a botnet, but it is on track to be the most successful, with the number of systems infected at more than 1 million. Storm is one of the first peer-to-peer botnets that can be controlled from several different servers.

Grum—2008

Grum is a massive pharmaceutical spammer bot that was identified in 2008. It appeared to be more complex and larger beyond the imagination of the experts. During Grum’s demise in July 2012, it was able to send 18 billion email spams per day.

Kraken—2008

Remember Storm botnet? Now imagine a botnet that is twice as powerful as Storm, and that is how big Kraken is. Damballa, an internet security company, was the first to report Kraken. Unlike, peer-to-peer techniques, Kraken uses command and control servers located in different parts of the world.

Mariposa—2008

Originated in Spain in 2008, Mariposa botnet hijacked around 12.7 million computers around the world in 2 years duration. The word “Mariposa” stands for butterfly in French. The botnet got its name because it was created with a software called Butterfly Flooder, which was written by Skorjanc illegally.

Methbot—2016

Methbot is the biggest ever digital ad malware that acquired thousands of IP addresses with US-based ISPs. The operators first created more than 6,000 domains and 250,267 distinct URLs that appeared to be from premium publishers, such as ESPN and Vogue.

Mirai—2016

Mirai infects digital smart devices that run on ARC processors and turns them into a botnet, which is often used to launch DDoS attacks. If the default name and password of the device is not changed then, Mirai can log into the device and infect it. In 2016, the authors of Mirai software launched a DDoS attack on a website that belonged to the security service providing company.

3ve—2018

3ve botnet gave rise to three different yet interconnected sub-operations, each of which was able to evade investigation after perpetrating ad fraud skillfully. Google, White Ops, and other tech companies together coordinated to shut down 3ve’s operations. It infected around 1.7 million computers and a large number of servers that could generate fake traffic with bots.

Botnets have been a constant threat to the IT infrastructure of the industry, and dealing with them requires an aggressive, assertive, and skilled cybersecurity approach. If you want to be a pro in combating botnet attacks and other similar cybersecurity attacks, you should be a Certified Ethical Hacker (C|EH).